Structural square tubing as pneumatic manifold

[newby81]

Hi There,

I have recently designed a part for our machine out of 101.6x101.6x4mm structural square tubing with 4mm thick end caps welded onto each end of the structural member. The intention was to use this square tubing as our pneumatic manifold rather than manufacturing and bolting on a separate manifold.

After giving it some thought, I have become nervous to pursue this design concept as I am not certain that the structural tube has enough integrity to be used as a pneumatic manifold.

Is it possible for us to use the tube mentioned above in the manner I have described?

My manager has suggested that I carry out some calculations to verify if the tube will be up to the task but I haven't got a clue where to even start with such calculations.

Thank you.

 

[pperlich]

Depending on pressure, wall thicknesses, and weld quality it can be done. I suggest either finding someone competent in pressure vessel design and hiring them to run the calcs, or hiring a tank fabricator to design and build the vessel.
A failure could be much more costly.

 

[newby81]

Thank you pperlich.

Sorry, I did forget to mention the intended pressure. Currently it is 6 Bar. Wall thickness is 4mm.

 

[EdStainless]

At that pressure had it over to a pro.

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P.E. Metallurgy, Plymouth Tube

 

[JStephen]

A quick back-of-the-envelope check shows that it is fairly highly stressed, and likely wouldn't meet something like the ASME pressure vessel code.

The structural tubing material likely won't be included in a pressure vessel or piping specification, so you may not be able to fully comply with those standards. The corner radius may be fairly variable, and would likely need to be confirmed for the calculations.